code-server: remove unused playwright patch

Reference was removed in https://github.com/NixOS/nixpkgs/pull/198791

pkgs/servers/code-server/playwright.patch

@@ -1,10 +0,0 @@
---- ./vendor/modules/code-oss-dev/node_modules/playwright/install.js
-+++ ./vendor/modules/code-oss-dev/node_modules/playwright/install.js
-@@ -14,6 +14,4 @@
-  * limitations under the License.
-  */
- 
--const { installDefaultBrowsersForNpmInstall } = require('playwright-core/lib/utils/registry');
--
--installDefaultBrowsersForNpmInstall();
-+process.stdout.write('Browser install disabled by Nix build script\n');